The present invention relates to turn indicator signals for vehicles, and particularly to the use of a gyroscope to effect the automatic cancellation of a turn indication. The present invention is applicable to all vehicles, but it is considered that the invention is particularly useful as applied to two wheeled vehicles, such as motorcycles. Therefore, although the invention is described herein at times specifically in relation to motorcycles, it is understood that it is not limited thereto.
Vehicle turn indicator signals are generally well known in the art. An operator closes a double throw switch from a neutral open position to one closed position to signal a left turn, or to the other closed position to signal a right turn. An appropriate set of lights operated through a flasher, usually a thermal flasher, is actuated to indicate the intended direction of turn. Upon completion of the turn, the switch is returned, preferably automatically, to its neutral position to cancel the turn signal.
In four wheeled vehicles, automatic cancellation of a turn indicator signal is most commonly effected through a mechanical mechanism associated with the steering column. However, in the case of motorcycles, turns are often effected with only slight and nearly imperceptible turning of the steering column or front wheel fork. Therefore, the conventional approach used on four wheeled vehicles to cancel turn indicator signals cannot be used effectively on motorcycles. Accordingly, it has been proposed to rely on inertial or gravitational means, such as a specially designed mercury switch or pendulum, to effect automatic cancellation of turn signals on motorcycles, as suggested for example in U.S. Pat. No. 3,876,976 to R. H. Cross, Jr.. However, because the turning of a motorcycle depends upon a combination of turning of the front wheel and lean of the vehicle, such inertial devices are not entirely reliable.
In accordance with the present invention, automatic cancellation of a turn signal is controlled by a gyroscope, which provides an effective and reliable cancellation operation, except possibly on the slightest degree of turn, as may be experienced for example in a lane change. A manually operated double throw switch is moved from a neutral open switch position to one of two closed switch positions to energize a flasher circuit for actuating either a left turn or right turn signal. The manual switch is retained in the selected closed position by a detent latch structure, or the like. When the vehicle is then turned in the direction indicated, a gyroscope mounted on the vehicle is caused to precess; and when the turn is completed, a resilient restraining means causes the gyroscope to return to its starting position. This precession movement of the gyroscope, and particularly the return movement, is utilized to cancel the turn signal. Thus, it will be appreciated that turn signal cancellation results from a change in heading or direction of the vehicle, and is accomplished independently of either the lean of the vehicle or the movement of its steering column. The invention is therefore particularly well adapted to use on motorcycles, although it is not limited thereto.
It is therefore one object of the present invention to provide for the automatic cancellation of a vehicle's turn indicator signal upon completion of a turn.
Another object of the present invention is to provide for such cancellation as a result of a change in heading of the vehicle, independently of the lean of the vehicle or the movement of its steering column.
And still another object of the present invention is to provide for the automatic cancellation of a turn indicator signal upon completion of a turn, which is particularly suited for two wheeled vehicles, such as motorcycles.